Excessive tearing, or “epiphora,” in canines is manifested by a watery ocular discharge and is a very common concern of pet owners. Environmental, genetic and emotional factors contribute to canine epiphora. In dogs having particularly large eyes or certain facial bone structures, epiphora may be an inherited and irreversible part of their anatomy. Teething puppies exhibit the symptoms of epiphora more frequently than adult dogs. Dogs with small or clogged tear ducts are also particularly prone to epiphora. Fleas are a potential cause of epiphora since they are likely to benefit from the dampness around the dog's eyes. Epiphora in dogs may also be diet-related. Foods with dyes or water having a high mineral content can cause epiphora.
Tear staining associated with epiphora is a common problem. In a recent survey, 89% of Maltese, Bichon, Havanese, Lhasa and Terrier owners indicated that their dogs were afflicted with staining of the facial hair due to excessive tearing. When canine facial hair becomes wet due to excessive tearing, the hair becomes a breeding ground for bacteria and yeast, such as Ptyrosporin or Red Yeast, which causes a deep reddish-brown stain. Such facial hair staining does not indicate a poor quality or a poorly bred, dog, nor is it an indication that the dog is neglected, mistreated or unhealthy. It simply indicates that the dog tears excessively and/or drains tears to a lesser extent than is necessary for any of a number of possible reasons.
An unconstrained ear infection can also be the cause of excessive tearing and facial hair staining. Proper care is necessary to ensure that after bathing, the dog's ears are dried thoroughly. Sporadic growth of hair in the ears should also be gently pulled out using a forceps. Frequent cleaning of a dog's ears can also contribute to prevention of canine ear infections and resultant staining.
Various conventional preventative measures have been undertaken to combat canine tear staining. These include keeping the dog's eyes clean, since tears drain down the dog's face and the exposure of bacteria and fungi to moisture produces skin irritation, infection and odor. In some dog breeds, hair has a tendency to grow from the face and into the eye and cause eye irritation. Moreover, eyelashes can grow at abnormal angles and rub on the eye. Therefore, regular grooming can significantly reduce eye irritation and resultant tearing and staining. Other preventative measures to reduce excessive canine tearing include having the dog checked at least twice a year for ear infections and ear mites, gum infections, common yeast or bacterial infections of the eye (especially Red Yeast) and for clogged tear ducts; maintaining a healthy diet; maintaining good hygiene; and reducing stress.
Although conventional preventative measures are important, they are oftentimes insufficient to eliminate the problem of excessive tearing, since excessive tearing may be due to unchangeable factors such as a dog's heredity or propensity to excessive chewing while cutting new teeth. Medications that treat tear staining are available by prescription. These include Tetracycline, for example. However, a disadvantage associated with the use of Tetracycline to treat excessive tearing is that Tetracycline has a tendency in many canines to cause upset stomach, which contributes to additional tear staining, as well as staining of the teeth.
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There is an unmet need for an edible product that is palatable and contributes to the elimination or reduction of tear staining, especially in cases in which conventional measures are ineffective, and which is safe for daily use.